Based on ecological and morphological features, the 300 or more haplochromine cichlid species of Lake Victoria are classified into fifteen (sub)trophic groups. A key to the trophic groups, mainly based on external morphological characters, is presented. Of each trophic group a description is given comprising data on taxonomy, ecology and fishery. As far as possible data from the period before the Nile perch upsurge and from the present situation are compared. A list of described species classified into trophic groups is added.